Lasioglossum (Dialictus) pruinosum (Robertson)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 159

Lasioglossum (Dialictus) pruinosum (Robertson)

Halictus pruinosus Robertson, 1892: 269 . Ƥ 3.

Lectotype. Ƥ USA, Illinois, Macoupin Co., Carlinville, 22.v.1891 (C. Robertson); [INHS: 11121] by W. E. LaBerge (in Webb 1980). Examined.

Taxonomy. Robertson, 1902b: Chloralictus pruinosus , p. 248 (key); Cockerell, 1909: Halictus pruinosus , p. 9 (tax. comp.); Michener, 1951: Lasioglossum (Chloralictus) pruinosum , p. 1116 (catalogue); Mitchell, 1960: Dialictus pruinosus Ƥ3, p. 415. (redescription); Krombein, 1967: Lasioglossum (Dialictus) pruinosum , p. 465 (catalogue); Dialictus pruinosus , p. 1970 (catalogue); Moure & Hurd, 1987: Dialictus pruinosus , p. 125 (catalogue); Gibbs, 2010b: Lasioglossum (Dialictus) pruinosum Ƥ3, p. 269 (redescription, key).

Diagnosis. Female L. pruinosum can be recognised by the following diagnostic combination: head long (length/ width ratio = 1.05–1.09); mesoscutal punctation dense (i<d), except on medial portion (i=1–1.5d); mesepisternum rugulose; wings hyaline; pterostigma nearly white pterostigma; and metasomal terga with abundant tomentum. They are most similar to L. succinipenne , which has the mesoscutal punctures dense throughout.

Male L. pruinosum can be recognised by the following diagnostic combination: head long (length/width ratio = 1.18–1.21), covered in dense white tomentum; clypeus with distal yellow maculation; flagellomeres short (length/width ratio = 1.15–1.30), bright yellow ventrally; mesoscutal punctation moderately sparse medially (i=1–2d); mesepisternum rugoso-reticulate; and metasomal terga bluish green, distinctly punctate. They are most similar to L. albipenne , which lacks yellow on clypeus and have brown metasomal terga.

Range. British Columbia and south to Arizona east to north-eastern USA. USA: AZ, CO, IA, ID, IN, MI, MN, NE, TX, UT, WI. CANADA: AB, BC, MB, SK.

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon in the eastern United States. See Gibbs (2010).